Less than 24 hours after Sayfullo Saipov turned his truck into a weapon and killed eight people in downtown New York, attention has swiftly turned to his country of birth 6,000 miles away — Uzbekistan.

“Why Does Uzbekistan Export So Many Terrorists?” asked The Atlantic. “Central Asia Is Seen as Breeding Ground of Militancy,” announced the New York Times. The hunt is on for answers as to why Saipov turned into the murderer that he is.

But we’ve been here before.

Each time a foreign-born attacker strikes the US the instinct has become to search their origins abroad. Most tellingly, this happened in the case of the Boston Marathon bombing, when investigators, analysts, and journalists spent months combing through the Tsarnaev brothers’ Dagestani origins, rather than looking at what ultimately radicalized them as they failed to acclimate to the United States.

I was working at the Guardian in Moscow at the time and was promptly dispatched to Dagestan, where I worked to piece together their childhood and family history. I wish I had taken the words of the director of the brothers’ childhood school more seriously. “They were socialized in America,” Magomed Daudov said. “The question has to be asked: why, having studied well, in good schools, were they socialized in such a way that they were forced to commit this incomprehensible act?"

Now here we are again. Uzbekistan, like Dagestan, is a post-Soviet part of the world (unlike Dagestan, it is not a part of Russia, despite what you might have heard). And like Dagestan, its population is mainly Muslim. And also like Dagestan, it has elements of an Islamist insurgency. And finally, also like Dagestan, it has had citizens join ISIS in Syria and commit acts of terror around the world.

But, like the Tsarnaevs, Saipov had been living in the United States for years before deciding to strike on Tuesday evening. Saipov moved to the US in 2010, leaving behind a country that had been ruled by a brutal strongman known for vast human rights abuses, including boiling people alive.

In the 24 hours since he attacked, we have learned little of Saipov's American life. We know he is married and has three children. We know he has a Florida’s driver’s license and has lived in Ohio, Florida and, most recently, in New Jersey. We know he worked as an Uber driver.

Saipov left notes pledging allegiance to ISIS at the site of his attack so the question will surely turn to how he was radicalized.

Former neighbors in the Uzbek capital of Tashkent told RFE/RL that the Saipov family was “very secular” and “ordinary Uzbeks who don’t stand out in any particular respect.” An acquaintance who met Saipov in Ohio shortly after he arrived in the US told the outlet that he was not “[very] religious” when he arrived.

John Miller, the New York Police Department’s deputy commissioner of intelligence and counterterrorism, said Saipov appears to have followed “almost exactly to a ’T’ the instructions that ISIS has put out in its social media channels” on how to carry out such an attack, including leaving notes. “The gist of the note was that the Islamic State would endure forever,” he said.

Speaking on CNN, Governor Andrew Cuomo said: "He was associated with ISIS and he was radicalized domestically and he’s a depraved coward.”

ISIS has encouraged its followers to carry out attacks with cars. In its appeals, and instructions, outlined in Dabiq magazine, it has also urged followers to leave notes behind, as Saipov did.

The coming days will be filled with questions as the city and the country try to understand what motivated Saipov to turn to terror. Analysts can look at Uzbekistan, the country Saipov left four years before ISIS came into existence.

Or they can ask the tough questions that have plagued the US, and countries around the world: How do people radicalize domestically? How do you battle a group with a diffuse network that can convert basic tools like cars into weapons of terror? And how, in the end, do you deny them further adherents? That’s a question best answered at home.

Miriam Elder is the world editor for BuzzFeed News and is based in New York. Her secure PGP fingerprint is 5B5F EC17 C20B C11F 226D 3EBE 6205 F92F AC14 DCB1